Programming languages exist to allow programmers to make sense of complex real-world problems. What real world scenarios lend themselves to modelling by objects, and which to functions?
The first time I met objects was in Turbo Pascal in about 1990. I was completely baffled. I eventually got comfortable with objects in c++, and had that turned on its head by Smalltalk. Then Java objects came along and made me write too much code. Ruby was a breath of fresh air, but it took me 8 years before I really grokked the object model in Ruby. Lately with all the interest in functional languages, I've been glimpsing some overlaps between functions and objects.
I'm still not sure if CLOS is a good idea though.
Accompanied by real-world code examples in Ruby, naturally.